Piperazine derivatives



2,988,551 Patented done 13, 1961 chloride and 0.2 mol of 1,4-bis-(Z-hydroxyethyD-piper- PIPERAZAT azine is heated with mechanical stirring at 150 C. for

3 hours.

After cooling, the mass is treated with an aqueous solu- 5 tion of caustic soda, and extracted with benzene. The benzene solution is evaporated, and by distillation there is obtained at first 0.071 mol of l-(2-p-chlorobenzohydryloxyethyl)-4-(2-hydroxyethyl)-piperazine, boiling at 217 i C./ 0.05 mm. Hg, and then 0.01 mol of l,4-bis-(2-p-chlo- The present invention relates to the preparation of 0 robenzohydryloxyethyl)-piperazine, boiling at 290 C./ compounds of the general formula 0.05 mm. Hg.

CHzOH, 0.1 mol of 1-(2-p-chlorobenzohydryloxyethyl)-4-(2- I hydroxyethyD-piperazina is dissolved in 100 ml. of benv CHZCH O R zene, and this solution is treated in the cold with 0.11 oHiCHs 15 mol of thionyl chloride. The mixture is then heated on Formula A the water bath until the liberation of sulphurous anhywherein R is a benzohydryl radical which may be subdrideis finished- The p -(?-P- 1- stituted by a halogen atom, an alkoxy radical or an alkyl zohydryloxyethyl)'4'(2'ch1P1'ethY1)'PIPeraZme crystaulzes radical of not more than six carbon atoms; wherein R P coolmg- 3 solvent 15 evaporated and the Tesldue is identical with R, or an alkyl of not more than eight taken up Wlth anhydrous Peetone, Q filtered carbon atoms, a hydroxyalkyl, cycloalkyl, phenylo r mol of the i pmdufit thus obtamefibenzyl radical which may be substituted by a halogen The corieswndmg base 18 llbetateii by dlssolvmg g atom or from 1 to 3 alkyl or alkoxy radica1s Y hydrochloride in water. The solution is rendered alkaline These products have important biological Properties with potasslum carbonate, and extracted with benzene. especially in the field of allergy. 'Some of them countere benzene solution 1s dehydrated with potassiumcaract 800 to 1000 toxic histamine doses bonate. The dehydrated solutlon 1s added to an equlmo- The process of preparing'these compounds. comprises f quanmy Sodmm methylene m h q ifl reacting an alcoholate or a phenolate on a compound of 9 i whole heated under reflux for hl 11* the general formulae is evaporated to dryness, and then taken up with aqueous Henri Morten, Brussels, Belgium, assignor to Union Chimique Belge, S.A., Brussels, Belgium, a corporation of Belgium No Drawing. Filed July 26, 1955, Ser. No. 524,615

Claims priority, application Belgium July 30, 1954 8 Claims. (Cl. 260-268) OHQCm caustic soda solution and extracted with benzene. By

distillation of the benzene solution, 1-(2-p-chlorobenzo- FPO-GENE}: NCHflCHRHa hydryloxyethyl)-4-(2-methoxyethyl)-piperazine, boiling at CH2C i I 199 C./ 0.02 mm. Hg, is obtained with 83 percent yield.

cHgoHz For preparing the di-hydrochloride, the base is dissolved in ethanol While passing a stream of gaseous hy- N CHYCHiHal drochloric acid through it. The salt is precipitated by an OHiCHi excess of ethyl ether. The dihydrochloride can be puriwherein R and R have-the aforesaid significance, and fied y dissolving in a Small q y of ethanol and Hal denotes a halogen atom. These compounds are obreprecipitafing with ethyl ethertained from 1,4-bis-(2-hydroxyethyl)-piperazine by reacting the latter at first with a halide of R or R, and then with thionyl chloride.

'I he ethers described in this specification are all new.

EXAMPLE 2 The following examples specify the characteristics of these Y A mixture consisting of 0.4 mol of 1,4-bis-(2-hydroxyproducts.

ethyD-piperazine and 0.2 mol of p-tert.-butylbenzy1 bro- EXAMPLE 1 a g nude is heated to 180-190 C. for 3 hours. The mixture 1s then distilled off under high vacuum. 1-(2-hydroxyethyl)-4-(2-p-tert.-butylbenzyloxyethyl)-piperazine, boiling at 155,160 C./ 0.002 mm. Hg is obtained at first, and then 1,4-bis-(2-p-tert.-butylbenzyloxyethyl) piperazine,

6 boiling at 220 C./0.002 mm. Hg. Cl\ CH2CH2 s 9.7 gm. of 1-(2-hydroxyethyl)-4-(2-p-tert.-butylbenzylp a a -oxyethyl)-piperazine are dissolved in ml. of benzene.

I (2 p chlorobenzohydryloxyethyl) 4 (2 methoxyethyl) piperazine and 1,4 bis (2 p chlorobenzohydryloxyethyl)-piperazine Al CH CH 4.1 gm. of cold thionyl chloride are added thereto. The mixture is then heated under reflux for 2 hours. After C-O-OHaCHzN NOHzCHr-O-O consisting of 0.1 molof p-chlorobenzohydryl, heating is stopped, the disengagement of sulphurous anhydride has completely ceased. The hydrochloride formed is isolated and heated with an aqueous solution of sodium bicarbonate, extracted with benzene, and the solution is treated with active carbon. It :is dried and evaporated to dryness. Crude l-(2-chlorethyl)-4-'(2-p tert.-butylbenzyloxyethyl)-piperazine is thus obtained. This product is added to the sodium derivative prepared from 21 gm. of p-methoxybenzohydrol and 0.7 gm. of metallic sodium in 75 m1. of toluene. The mixture is heated under reflux for 2 hours. The toluene is then evaporated and the product is heated to ISO-160 C. for 3 hours.

After cooling, the product is treated with an aqueous alkaline solution, and extracted with benzene. By distillation there is obtained 1-(2-p-methoxybenzohydryloxyethy1)-4-(2-p-tert.-butylbenzyloxyethyl)-piperazine having a melting point of 260 'C./ 0.002 mm. Hg.

EXAMPLE 3 1-(Z-p-n-hexylbenzohydryloxyethyl)-4-(2-cyclohexyloxyethyl) -piperazine This compound, having a melting point of 255 C./ 0.005 mm. Hg is obtained according to the method described in Example 1 by reacting sodium cyclohexylate with 1-(Z-p-n-hexylbenzohydryloxyethyl) -4- (Z-chlorethyl)-piperazine.

This substance is prepared as follows:

Benzoyl chloride is caused to react upon n-hexylbenzene in the presence of aluminium chloride. In this way p-n-hexylbenzophenone is formed (B.P. 180 C./2 mm. Hg; M.P. of the dinitrophenylhydrazone (119 C.). This product is reduced (for example by zinc and ethanolic sodium hydroxide) and thus transformed into p-nhexylbenzohydrol (B.P. 150 C./0.0l mm. Hg) which by treating with hydrochloric acid is converted into p-n-hexylbenzohydryl chloride. By reacting it with 1,4- bis-(2-hydroxyethyl)-piperazine there is' obtained l-(2- p-n-hexylbenzohydryloxyethyl)-4-(2 hydroxyethyl) piperazine having a melting point of 230-235 C./0.05 mm. Hg. This compound is converted by thionyl chloride into 1-(Z-p-n-hexylbenzohydryloxyethyl)-4-(2-chlorethyl)-piperazine.

. EXAMPLE 4 Preparation of other 1,4-diethanl-pipemzine derivatives By the process described in Example 1 theremay be prepared the compounds corresponding to the following general formula:

CHaCH:

Formula B v l- (2-benzohydryloxyethyl) 4 [Z'.(2'-ethylbutoxy) ethyl1-piperazine.

Formula B, wherein V R=H, and R (C2115) 3 B.P. 220 C./0.05 mm. Hg. l-(Z-benzohydryloxyethyl) -4-(2-cyclohexyloxyethyl) piperazine.

Formula B wherein R=H and CHQCHI /CH: CHaCH:

B.P. 245 C./0.05 mm. Hg. 1-(2-benzohydry1oxyethy1)-4-[2-(4' methoxycyclohexyloxy) -ethyl] -piperazine.

Formula B wherein R=H and CHnCHg CH-OCHK B.P. 243 C./0.02 mm. Hg.

CHsCH) CHaCHl I-(Z-benzohydryloxyethyl)-4 (2 phenoxyethyl) piperazine.

Formula B wherein R=H and R'=C H B.P. -185" C./l.5 mm. Hg. 1 ,4-bis-(2-benzohydryloxyethyl -piperazine.

Formula B wherein R=H and B.P. 250-255" c./o.01 mm. Hg. r

' 1-(2-p-chlorobenzohydryloxyethyl) 4-(2 tert. butoxy CHKJ H1 B.P. 270 C./0.04 mm. Hg. 1-(2-p-ehlorobenzohydryloxyethyl)-4-(2 m methylphenoxyethyD-piperazine.

Formula B wherein R=Cl and Reg Ha B.P. 235 C./0.05 mm. Hg. 1-(2-p-chlorobenzohydryloxyethyl) 4-[2-2',6'-diisobutyl- 4'-methylphenoxy)-ethyl] piperazine.

2,988,551 I V s l-(2-p-chlorobenzohydryloxyethyl)-4-(2 'ci e lohexyloxyethyl)-piperazine.

o-o-oHioH,N Nomomo-t on, 6/11 CHICfi: CHzC B.P. 238 C./0.05 mm. Hg. by reacting 1,4-bis-(2-hydroxyethyl)-piperazine with R 1-(2-p-chlo1'obenzohydryloxyethyl) -4-[*2-(4 methylcyclo- Hal and treating the reaction product with thionyl chlohexyloxy)-ethyl]-piperazine. 1 ride.

o-o-omomN Nomcm-o-o 0H1 B.P. 244 C./0.05 mm. Hg. 3. A compound selected from the group consisting of The dihyd-rochloride of all the bases is obtained as the ethers of 1,4-diethanol-piperazine having the formula described in Example 1. CHZCHI I claim: v

1. A process of preparing ethers of 1,4-diethanolpiperazine of the formula CHfl 1 wherein R is a radical selected from the group consisting U u v of benzhydryl, monochlorobenzhydryl, monoalkoxybenz- R-O-CHzCHaN NCHaGH!* hydryl and monoalkylbenzhydryl, the alkoxy and alkyl CHCH, groups containing one to six carbon atoms, and wherein R is a radical selected from the group consisting of 1 V to 8 carbon alkyl, 1 to 8 carbon hydroxyalkyl, cyclowherem R a radlcal selected from the group conslst' hexyl, phenyl, benzyl, and substituted cyclohexyl, phenyl ing of benzhydryl monochlombenzhydryl monoalkoxy' and hem 1 wherein the substituent is selected from the benzhydryl and monoalkylbenzhydryl, the alkoxy and group cogsisfing of a chlorine atom, 1 to 3 alkyl radi alkyl groups containing one to six carbon atoms, and H l wherein is a radical Selected r the g p Consist cals, and 1 to 3 alkoxy radicals, and the dihydrochlorrdes thereof. ing of 1 to 8 carbon alkyl, 1 to 8 carbon hydroxyalkyl, cyclohexyl, phenyl, benzyl, and substituted 'cycl'ohexyl, g' g'i ggigggg 4 (2 ten but phenyl and benzyl wherein the substituent is selected 5' d l ethyl)-4 (2 -n-hexylfrom the group consisting of 'a chlorine atom, 1 to 3 alkyl radicals, and l to 3 alkoxy radicals, said process comprising the step of reacting a compound selected from the group consisting of the alcoholate's and phenolates of 40 the formula R'-O Na with a compound of the formula oxyethyl) -piperazin'e.

6. 1-(2-p-chlorobenzhydryloxyethyl)-4-[2-(4 methylcyclohexyloxy) -ethyl] -pipera'zine.

7. 1-(2-p-chlorobenzhydryloxyethyl) '-4-(2-p methoxybenzyloxyethyl)-piperazine.

8. 1-(Z-p-chlorobenzhydryloxyethyl) 4 [2 (3,5 di- /CHCH; methylbenzyloxy) -ethyl] -piperazine. H References Cited in the file of this patent 0 2C 2 UNITED STATES PATENTS l I 2,527,962 Rieveschl Oct. 31, 1950 wherein Hal 1s a halogen atom selected from the group 12 527 9 3 Rieve-schl Oct 31 1950 consisting of the chlorine atom and the bromine atom.

2. A process as defined in claim 1, further compris- OTHER REFERENCES ing the step of forming the compound of the formula Ratner: Allergy, Anaphylaxis and Immu'notherapy,

page 382 (1943). CH CH Fieser and Fieser; 2nd edition, p. 137 (1950). I I 5 Hazard et a1.: Arch. Inter. Pharmacodynamie, 84, 237- w-o-cmoum Nomomna I 256 (1950).

g, Chem. Abstracts, vol. 45, p. 577 1951). 

3. A COMPOUND SELECTED FROM THE GROUP CONSISTING OF THE ETHERS OF 1,4-DIETHANOL-PIPERAZINE HAVING THE FORMULA 